表面活性剂辅助分散液相微萃取-气相色谱法分析蔬菜水果中有机磷类农药残留

Detection of Organophosphorus Pesticides in Vegetables and Fruits by Surfactant-assisted Dispersive Liquid-phase Microextraction Coupled with Gas Chromatography

建立了测定蔬菜水果中有机磷类农药残留的表面活性剂辅助分散液相微萃取-气相色谱法。优化的萃取条件为:在5.0 mL样品溶液中加入50.0μL三氯甲烷和0.5mL 0.04 mmol·L-1的N-十二烷基-β-氨基丙酸盐表面分散剂,分散混匀后,以5 000r·min-1离心5min,吸取三氯甲烷相直接进样分析。在最优化条件下,8种有机磷类农药在0.02~0.50μg·mL-1范围内具有良好的线性关系,相关系数在0.9948~0.9985之间;检出限为0.0056~0.0110μg·mL-1。有机磷类农药的富集倍数高达264~537倍。方法应用于蔬菜水果中的有机磷类农药分析,加标回收率在82.4%~114.5%之间;相对标准偏差(RSD)在4.9%~13.7%之间。该方法具有操作简单、富集效率高和灵敏度高等特点,可满足蔬菜水果中有机磷类农药残留的检测。

A method was developed for the determination of organophosphorus pesticides residues in vegetables and fruits samples by surfactant-assisted dispersive liquid-phase microextraction（DLLME）coupled with gas chromatography（GC）.Some important parameters that influence the extraction efficiency were investigated.50.0μL chloroform and 0.5mL 0.04mmol·L^1 S-80 were rapidly injected into a 5.0mL sample solution.After centrifugation at 5 000r·min-1 for 5 min,the analytes that had been extrated into chloroform was directly injected into the GC for detection.Under the optimum conditions,agood linearity was obtained in the range of 0.02-0.50μg·mL^1 of the analytes with the correlation coefficients of 0.9948-0.9985 and the detection limits of 0.0056-0.0110μg·mL^1（S/N=3）,and enrichment factors of 264-537 were achieved.This method has been successfully applied for the determination of organophosphorus pesticides in vegetables and fruits with satisfactory results.The recoveries were in the range from 82.4% to 114.5% and the relative standard deviations（RSDs）were between 4.9% and 13.7%.The method is simply operated,and sensitive with high enrichment factor,and can be used to determine organophosphorus pesticides residues.